src/test/ui/proc-macro/expand-expr.rs

   1 // aux-build:expand-expr.rs
   2 #![feature(concat_bytes)]
   3 extern crate expand_expr;
   4
   5 use expand_expr::{
   6     check_expand_expr_file, echo_pm, expand_expr_fail, expand_expr_is, recursive_expand,
   7 };
   8
   9 // Check builtin macros can be expanded.
  10
  11 expand_expr_is!(11u32, line!());
  12 expand_expr_is!(24u32, column!());
  13
  14 expand_expr_is!("Hello, World!", concat!("Hello, ", "World", "!"));
  15 expand_expr_is!("int10floats5.3booltrue", concat!("int", 10, "floats", 5.3, "bool", true));
  16 expand_expr_is!("Hello", concat!(r##"Hello"##));
  17
  18 expand_expr_is!("Included file contents\n", include_str!("auxiliary/included-file.txt"));
  19 expand_expr_is!(b"Included file contents\n", include_bytes!("auxiliary/included-file.txt"));
  20
  21 expand_expr_is!(
  22     "contents: Included file contents\n",
  23     concat!("contents: ", include_str!("auxiliary/included-file.txt"))
  24 );
  25
  26 expand_expr_is!(
  27     b"contents: Included file contents\n",
  28     concat_bytes!(b"contents: ", include_bytes!("auxiliary/included-file.txt"))
  29 );
  30
  31 // Correct value is checked for multiple sources.
  32 check_expand_expr_file!(file!());
  33
  34 expand_expr_is!("hello", stringify!(hello));
  35 expand_expr_is!("10 + 20", stringify!(10 + 20));
  36
  37 macro_rules! echo_tts {
  38     ($($t:tt)*) => { $($t)* };  //~ ERROR: expected expression, found `$`
  39 }
  40
  41 macro_rules! echo_lit {
  42     ($l:literal) => {
  43         $l
  44     };
  45 }
  46
  47 macro_rules! echo_expr {
  48     ($e:expr) => {
  49         $e
  50     };
  51 }
  52
  53 macro_rules! simple_lit {
  54     ($l:literal) => {
  55         expand_expr_is!($l, $l);
  56         expand_expr_is!($l, echo_lit!($l));
  57         expand_expr_is!($l, echo_expr!($l));
  58         expand_expr_is!($l, echo_tts!($l));
  59         expand_expr_is!($l, echo_pm!($l));
  60         const _: () = {
  61             macro_rules! mac {
  62                 () => {
  63                     $l
  64                 };
  65             }
  66             expand_expr_is!($l, mac!());
  67             expand_expr_is!($l, echo_expr!(mac!()));
  68             expand_expr_is!($l, echo_tts!(mac!()));
  69             expand_expr_is!($l, echo_pm!(mac!()));
  70         };
  71     };
  72 }
  73
  74 simple_lit!("Hello, World");
  75 simple_lit!('c');
  76 simple_lit!(b'c');
  77 simple_lit!(10);
  78 simple_lit!(10.0);
  79 simple_lit!(10.0f64);
  80 simple_lit!(-3.14159);
  81 simple_lit!(-3.5e10);
  82 simple_lit!(0xFEED);
  83 simple_lit!(-0xFEED);
  84 simple_lit!(0b0100);
  85 simple_lit!(-0b0100);
  86 simple_lit!("string");
  87 simple_lit!(r##"raw string"##);
  88 simple_lit!(b"byte string");
  89 simple_lit!(br##"raw byte string"##);
  90 simple_lit!(true);
  91 simple_lit!(false);
  92
  93 // Ensure char escapes aren't normalized by expansion
  94 simple_lit!("\u{0}");
  95 simple_lit!("\0");
  96 simple_lit!("\x00");
  97 simple_lit!('\u{0}');
  98 simple_lit!('\0');
  99 simple_lit!('\x00');
 100 simple_lit!(b"\x00");
 101 simple_lit!(b"\0");
 102 simple_lit!(b'\x00');
 103 simple_lit!(b'\0');
 104
 105 // Extra tokens after the string literal aren't ignored
 106 expand_expr_fail!("string"; hello); //~ ERROR: expected one of `.`, `?`, or an operator, found `;`
 107
 108 // Invalid expressions produce errors in addition to returning `Err(())`.
 109 expand_expr_fail!($); //~ ERROR: expected expression, found `$`
 110 expand_expr_fail!(echo_tts!($));
 111 expand_expr_fail!(echo_pm!($)); //~ ERROR: expected expression, found `$`
 112
 113 // We get errors reported and recover during macro expansion if the macro
 114 // doesn't produce a valid expression.
 115 expand_expr_is!("string", echo_tts!("string"; hello)); //~ ERROR: macro expansion ignores token `hello` and any following
 116 expand_expr_is!("string", echo_pm!("string"; hello)); //~ ERROR: macro expansion ignores token `;` and any following
 117
 118 // For now, fail if a non-literal expression is expanded.
 119 expand_expr_fail!(arbitrary_expression() + "etc");
 120 expand_expr_fail!(echo_tts!(arbitrary_expression() + "etc"));
 121 expand_expr_fail!(echo_expr!(arbitrary_expression() + "etc"));
 122 expand_expr_fail!(echo_pm!(arbitrary_expression() + "etc"));
 123
 124 const _: u32 = recursive_expand!(); //~ ERROR: recursion limit reached while expanding `recursive_expand!`
 125
 126 fn main() {}